2sin(-5п/6) + 11cos(-7п/3) + sin7п/6 - 8cos2п/3

Question

2sin(-5п/6) + 11cos(-7п/3) + sin7п/6 - 8cos2п/3

Answer 1

2х(-1/2)+11x(1/2)-(1/2)-8x(-1/2)=-1+(11/2)-(1/2)+4=3+5=8